Bipolar electric coagulating and incising tweezers having two arms have been used in neurosurgical operations. The arms of these instruments comprise a perfusion connection port and bipolar electrodes connected to a high frequency generator, being mutually insulated and being forced so that its tip portion will maintain an open state. It has been possible to coagulate-or incise a tissue or a blood vessel by nipping such tissue or blood vessel with the tip portion of the tweezers and electrifying this with a high-frequency current. Further, there is provided a perfusion passage pipe on the surface at the inside of an arm, and a physiologic saline or any other liquid is drawn out. As a consequence, the pyrogenic temperature at the time of coagulating and incising maneuvers is lowered depending on the electrification of a high-frequency current. This makes it possible to minimize any damage to tissue and concurrently, enables one to prevent such degradation in the coagulating and incising abilities as is involved when burnt tissue portions adhere to the tip portion of the tweezers.
Shown in FIGS. 5, 6 and 7 is one example of such conventional tweezers. Since the visual field of the operator is acquired mainly by the space between the arms of bipolar electric coagulating and incising tweezers, an arrangement of a perfusion passage pipe 10' (FIG. 5) on the surface at the inside of the above arm 2' becomes an obstacle to the operator's visual field., Thus, if the nipping operation of tweezers is conducted, the tip portion 8' becomes difficult to see, in consequence of which it is hard to grasp the hemostatic or incising position exactly. Further, the arrangement of FIG. 5 also poses an obstacle to the operator's visual field, i.e., the housing portion 7' for fixing the perfusion connection port 11' and bipolar electrodes 5' 6' connected to a high-frequency generator is arranged on the straight line relative to the central axis of the arm grip portion 4'. If tweezers 1' are arranged within the operator's visual field S on the straight line ranging from the center R of the operator's visual field to the operational site as shown in FIG. 8, the above housing portion 7' and bipolar electric wire 12' come to enter into the visual field.